package com.lagou.edu.factory;

import com.lagou.edu.annotations.CustAutowired;
import com.lagou.edu.annotations.CustService;
import com.lagou.edu.utils.TransactionManager;
import java.lang.reflect.Method;
import java.lang.reflect.Proxy;
import net.sf.cglib.proxy.Enhancer;
import net.sf.cglib.proxy.MethodInterceptor;
import net.sf.cglib.proxy.MethodProxy;

/**
 * @author 应癫
 * <p>
 * <p>
 * 代理对象工厂：生成代理对象的
 */
@CustService(value = "proxyFactory")
public class ProxyFactory {


  @CustAutowired
  private TransactionManager transactionManager;

  /**
   * Jdk动态代理
   *
   * @param obj 委托对象
   * @return 代理对象
   */
  public Object getJdkProxy(Object obj) {

    // 获取代理对象
    return Proxy.newProxyInstance(obj.getClass().getClassLoader(), obj.getClass().getInterfaces(), (proxy, method, args) -> {
      Object result;
      try {
        transactionManager.beginTransaction();
        result = method.invoke(obj, args);
        transactionManager.commit();
      } catch (Exception e) {
        e.printStackTrace();
        transactionManager.rollback();
        throw e;
      }
      return result;
    });

  }


  /**
   * 使用cglib动态代理生成代理对象
   *
   * @param obj 委托对象
   * @return
   */
  public Object getCglibProxy(Object obj) {
    return Enhancer.create(obj.getClass(), new MethodInterceptor() {
      @Override
      public Object intercept(Object o, Method method, Object[] objects, MethodProxy methodProxy) throws Throwable {
        Object result = null;
        try {
          // 开启事务(关闭事务的自动提交)
          transactionManager.beginTransaction();

          result = method.invoke(obj, objects);

          // 提交事务

          transactionManager.commit();
        } catch (Exception e) {
          e.printStackTrace();
          // 回滚事务
          transactionManager.rollback();

          // 抛出异常便于上层servlet捕获
          throw e;

        }
        return result;
      }
    });
  }
}
